Referring to FIGS. 11 and 12, a prior art rapid detached connecting device and an opener head are illustrated. A front end of the rapid detached connecting device has an engaging portion. An engaging block 91 is installed within the engaging portion. A spring is installed after the engaging block 91. A buckling unit 92 is installed within the engaging portion. The buckling unit 92 resists against the engaging block 91. When the engaging block 91 is pushed inwards, the buckling unit 92 will insert into the engaging portion. A front end of the opener head has a driving end corresponding to various screws. A middle section of the opener head has an annular groove and the rear end of the opener head has a guide tapered end 93 with a smaller diameter. Thereby, the user can insert the opener head into the engaging portion of the rapid detached connecting device. When the guide tapered end 93 at the rear end of the opener head is inserted into the engaging portion, the opener head will press the engaging block 91. At the same time, the buckling unit 92 of the engaging portion will insert into the engaging portion and collapse into the guide tapered end 93 of the opener head (see FIG. 12). Therefore, it is difficult to insert the opener head and thus the buckling unit is difficult to be buckled to the annular groove of the opener head. Thereby, a trouble in use is induced.